Any vacancy on the bay district board shall be filled by appointment in the same manner as the vacating member was appointed.

Any member of the bay district board may be removed at any time in the same manner as he was appointed. If four-fifths of the members of the board of supervisors of a county request the removal of a member appointed by the city selection committee of such county, the city selection committee of such county shall meet within 20 days to consider the removal of such member.